fn main()
{
  let     v1 = (1, 2);
  let mut v2 = (3, 4);

  println!("V1: ({},{})", v1.0, v1.1);
  println!("V2: ({},{})", v2.0, v2.1);

  v2 = v1;
  println!("V2: ({},{})", v2.0, v2.1);
}